The problem is that even the permanents that come are tapped and cannot be used right away
And because this ability triggers upon entry, you don't have to particularly worry about keeping Trishula safe since you'll have already made good use of its effect
Energy advantage is one of the most important things in Pokemon, and having a card that keeps all your Energy in play is so good
If this card is sent to the Graveyard: You can target 1 "Frightfur" Fusion Monster in your Graveyard
Red has tons of these permutations, giving you options at all budget levels (Molten Disaster, Delayed Blast Fireball, Inferno, Bloodfire Colossus, etc.)
This is fine for us as a vast majority of our plays involve monsters that are already of the Zombie type, however if our opponent is not running a Zombie Deck, well tough luck they will be unable to make any summons as Zombie World only makes the monsters on field or graveyard Zombies, not the hand or Extra Deck